On 5/28/07, Hydra Liu <yuliu at shao.ac.cn> wrote:
>
> Assume there is a rule about function P[n](x) such as :
>
> P[n1](x) * P[n2](x) = sum( H(l) * P[l](x), l, 0,n2), where H() are
> coefficients
>
Shouldn't n1 appear somewhere on the right-hand side?
-s